从稳定运行的序列间歇式活性污泥(SBR)反应器中分离纯化得到一株好氧反硝化菌(实验室命名为CFY1),对菌株CFY1进行了形态观察、生理生化鉴定及16S r DNA基因序列分析,并对其好氧条件下的反硝化能力进行了考察。结果表明,菌株CFY1的菌落呈圆形,乳黄色,半透明,表面光滑,边缘不整齐,菌体细胞为短杆状,无芽孢,革兰氏染色呈阴性;氧化酶反应呈阳性,具有分解葡萄糖和淀粉以及还原硝酸盐的能力;菌株CFY1的16S r DNA序列经BLAST分析,与Gen Bank中施氏假单胞菌(Pseudomonas stutzeri)具有98.9%同源性,结合该菌株的形态和生理生化特征,可基本确定菌株为施氏假单胞菌(Pseudomonas stutzeri),NCBI Gen Bank登录号为KC253270;在摇床转速150 r·min-1、培养温度30℃及p H值7.2的培养条件下,24 h内能将113.6 mg·L-1的NO3--N降解为0 mg·L-1。
To understand the anaerobic degradation pathway of domestic sewage,three lab-scale upflow anaerobic sludge blanked reactors (UASB) were employed to study the degradation pathway of different particle size and the effect of temperature on this process.Under the operation conditions of the hydraulic retention time of 24 h,the MLVSS of approximate 11200 mg·L-1 and the water temperature at 10,15 and 20℃,the overall degradation pathway of soluble fraction was characterized according to zero-order kinetics.As for the colloidal fraction (between 0.45 and 4.5 μm),the degradation processes followed a first-order kinetic,and should firstly disintegrated into soluble fraction before finally degrading.In contrast,suspended solids (bigger than 4.5 μm) degraded to soluble and colloidal fractions according to first-order kinetics,and the colloidal fraction originating from suspended solids further degraded into soluble fraction which had the same degradation kinetics as the original soluble fraction.There existed the difference of temperature effect on different fraction degradation.Under the temperature at 20,15 and 10 ℃,the first-order rate constant of suspended solids depredating into collide was 4.97,3.01 and 1.01 d-1 respectively.Whereas the degradation of collide to soluble fraction was slightly affected by the temperature change.On the other hand,the zero-order degradation rate constant of soluble fraction was 0.26,0.18 g and 0.12 gCOD·gVSS-1d-1,respectively.
